Note 16 - Fair Value Measurements - Financial Assets and Liabilities Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Securities available for sale	$ 322,523	$ 379,195
Fair Value, Inputs, Level 3 [Member]
Securities available for sale	0	0
US Treasury Securities [Member]
Securities available for sale	9,998	14,987
US Government-sponsored Enterprises Debt Securities [Member]
Securities available for sale	53,438	128,114
US States and Political Subdivisions Debt Securities [Member]
Securities available for sale	46,680	42,154
Corporate Debt Securities [Member]
Securities available for sale	11,488	9,700
Fair Value, Recurring [Member]
Securities available for sale	322,523	379,195
Fair Value, Recurring [Member] | Cash Flow Hedging [Member]
Derivative - cash flow hedges	5,616	2,658
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Cash Flow Hedging [Member]
Derivative - cash flow hedges	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available for sale	322,523	379,195
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Cash Flow Hedging [Member]
Derivative - cash flow hedges	5,616	2,658
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Cash Flow Hedging [Member]
Derivative - cash flow hedges	0	0
Fair Value, Recurring [Member] | US Treasury Securities [Member]
Securities available for sale	9,998	14,987
Fair Value, Recurring [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available for sale	9,998	14,987
Fair Value, Recurring [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Securities available for sale	53,438	128,114
Fair Value, Recurring [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available for sale	53,438	128,114
Fair Value, Recurring [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] | Collateralized Mortgage Obligations [Member]
Securities available for sale	200,919	184,240
Fair Value, Recurring [Member] | Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] | Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available for sale	200,919	184,240
Fair Value, Recurring [Member] | Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]
Securities available for sale	46,680	42,154
Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available for sale	46,680	42,154
Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] | Corporate Debt Securities [Member]
Securities available for sale	11,488	9,700
Fair Value, Recurring [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available for sale	11,488	9,700
Fair Value, Recurring [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available for sale	$ 0	$ 0